454g plain flour 2.5 teaspoons baking powder
1 teaspoon bicarbonate of soda
230ml of buttermilk (or you can use ordinary milk, even it's is starting to just turn sour)
Mix together the flour, baking powder, bicarb and sugar in large bowl, cut the butter into small pieces, drop it into the bowl and then rub the butter into the flour mix. It should take around 7-10 minutes depending on the temperature of the butter. The mix should look like big breadcrumbs when it's done, with no big lumps of butter visible.
Slowly add the buttermilk or milk mixing as you go (I use a fork for this as it works well), keep adding the liquid until you have a firm dry-ish dough, it shouldn't be wet and sticky. You might find you don't need all the liquid as it depends on the absorbency of your flour. Just use what is needed.
Once it's a nice firm dry dough (not so dry as it crumbles up) then lift it out onto a floured flat surface and roll it flat until it's about 1cm thick.
Cut into rounds using any handy-sized cutter - if you don't have a cutter then grease the rim of a mug and use that instead.
Lay the rounds onto greaseproof paper on a flat baking tray, and then glaze the surface of the rounds. You can use either a beaten egg for this, or the remains of the milk liquid.
Pop into the oven on high heat (gas mark 7) or 230C if fan assisted electric oven, 265C if not. Bake for around 15-20 minutes in the centre of the oven.
When they are done they will look golden and smell delicious!